Dragon's Den investors traditionally say “I'm out” when they will not invest.
The short phrase became one of the programme’s most recognisable pieces of language. A dragon may say it after deciding that the valuation, product, market, risk or proposed ownership share is not attractive enough.
Saying “I’m out” usually signals that the investor will not continue negotiating with that entrepreneur. It does not necessarily mean that every dragon has rejected the pitch, because another investor may still make an offer.
The expression is often treated as a signature catchphrase of the British programme. Similar formats in other countries use different wording, but “I’m out” is closely identified with the Dragon's Den format.